Modernize more Diffusion controllers

Summary: Ref T4245. Standardize how context is read, minor updates / modernizations / consistency tweaks.

Test Plan:
  - Viewed a change.
  - Viewed brnaches.
  - Edited a commit.
  - Viewed tags.
  - Viewed history.
  - Added, edited and deleted a mirror.
  - Viewed push events.
  - Viewed a particular event.
  - Viewed ref disambiguation.
  - Viewed repository list.
  - Ran automation test.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T4245

Differential Revision: https://secure.phabricator.com/D14944

src/applications/diffusion/controller/DiffusionRepositoryListController.php

@@ -6,28 +6,10 @@ final class DiffusionRepositoryListController extends DiffusionController {
     return true;
   }
 
-  protected function processDiffusionRequest(AphrontRequest $request) {
-    $controller = id(new PhabricatorApplicationSearchController())
-      ->setQueryKey($request->getURIData('queryKey'))
-      ->setSearchEngine(new PhabricatorRepositorySearchEngine())
-      ->setNavigation($this->buildSideNavView());
-
-    return $this->delegateToController($controller);
-  }
-
-  public function buildSideNavView($for_app = false) {
-    $viewer = $this->getRequest()->getUser();
-
-    $nav = new AphrontSideNavFilterView();
-    $nav->setBaseURI(new PhutilURI($this->getApplicationURI()));
-
-    id(new PhabricatorRepositorySearchEngine())
-      ->setViewer($viewer)
-      ->addNavigationItems($nav->getMenu());
-
-    $nav->selectFilter(null);
-
-    return $nav;
+  public function handleRequest(AphrontRequest $request) {
+    return id(new PhabricatorRepositorySearchEngine())
+      ->setController($this)
+      ->buildResponse();
   }
 
   protected function buildApplicationCrumbs() {